The present invention relates to a process for synthesizing a substituted pyrazole. The compound is particularly useful as an anti-diabetic compound. In particular, the compound has demonstrated activity as a glucagon receptor antagonist.
Glucagon serves as the major regulatory hormone attenuating the effect of insulin in its inhibition of liver gluconeogenesis and is normally secreted by α-cells in pancreatic islets in response to falling blood glucose levels. The hormone binds to specific receptors in liver cells that triggers glycogenolysis and an increase in gluconeogenesis through cAMP-mediated events. These responses generate glucose (e.g. hepatic glucose production) to help maintain euglycemia by preventing blood glucose levels from falling significantly.
In addition to elevated levels of circulating insulin, type II diabetics have elevated levels of plasma glucagon and increased rates of hepatic glucose production. The compound that is the subject of the process described herein in an antagonist of glucagon, and thus useful in improving insulin responsiveness in the liver, decreasing the rate of gluconeogenesis and lowering the rate of hepatic glucose output resulting in a decrease in the levels of plasma glucose.
One object of the present invention is to provide a process wherein the protecting groups are easily removed without resort to harsh deprotection conditions.
Another object of the present invention is to provide a process which facilitates selective deprotection.
These and other objects will be apparent from the teachings contained herein.